1. Field of the Invention
The invention relates to a device for the alternate winding-up and unwinding of strip-shaped material, particularly strand-cast thin slabs in furnace pairs, consisting of two furnaces that are located one above the other and have horizontal winding axles. In which device the furnaces can be swung from a winding-up position into an unwinding position and winding-up and unwinding take place at different speeds.
2. Description of the Prior Art
A generic winding device is known, for example, from DE 40 13 582 C1. This device is integrated into a unit which produces a hot-rolled strip of strand-cast input material, and it serves to compensate for the differences in speed between the strand casting and the rolling by temporarily storing the strip. The winding-up of the strip occurs in furnaces, so that uniform temperature conditions are achieved for the subsequent processing of the strip, which is then unwound from the furnaces, in the downstream finishing rolling mill.
Another winding device with furnaces located one above the other is known from EP 01 77 187 A1. In this device, in a manner similar to that known from DE 40 13 582 C1, the furnaces are alternately used for winding-up the strip, and the furnace which is not being used at a given time for winding-up the strip feeds the rolling mill by unwinding the previously wound-up strip.
The generic solution calls for the furnaces to be closed to large extent, in order to minimize heat loss during the winding-up and unwinding of the strip.
Both of the solutions described above require the strip-shaped material being wound-up, such as the strand-cast thin slab, to be fed in the same direction as the direction in which the unwound material is borne away, i.e., the rolling mill must be aligned with the upstream unit, which may be a thin-slab casting machine or the roughing train of a wide-strip train. However, space conditions often do not permit these two elements to be lined up in a straight line in front of and behind the furnace, particularly when existing units are being rebuilt. In such cases, the known winding-up and unwinding devices cannot be used. Although the idea of providing furnace pairs, each of which consists of two furnaces located one above the other on a shared rotary table is known from DE-PS 972 603 (FIGS. 3 and 4), which would theoretically allow the winding-up and unwinding sequences to be carried out in different directions, the furnace pairs in the known solutions are attached to the shared rotary table in such a way that while winding-up is in progress, unwinding in a different direction is not possible.